title: Mosaic pregnancy after transfer of a "euploid" blastocyst screened by DNA microarray.
abstract: BACKGROUND
  High proportions of human embryos produced by in vitro fertilization are aneuploidy and mosaic. DNA microarray is one of the most practical screening methods to select euploid embryos for transfer. However, mosaic pregnancy is still possible due to embryonic mosacism. Here we report a successful pregnancy after transfer of a mosaic blastocyst with euploid inner cell mass.
  
  
  METHODS
  A woman with a previous trisomy 13 pregnancy pursued infertility treatment with preimplantation genetic screening by a trophectoderm biopsy and DNA microarray. NimbleGen oligonucleotide DNA microarray was applied to biopsied samples from 13 blastocysts. A euploid blastocyst was transferred to the patient and subsequent prenatal cytogenetic tests were performed by FISH and/or G banding.
  
  
  RESULTS
  Following DNA microarray, it was found that 5 blastocysts were euploid and 8 were aneuploidy. Transfer of one euploid blastocyst resulted in a clinical pregnancy. Prenatal cytogenetic tests of samples biopsied from chorionic villi sample showed both trisomy 21 (47 XX, +21) and euploid (46, XX) cells. Further prenatal cytogenetic test with a sample from amniotic fluid indicated that all cells were euploid (46, XX). The pregnancy was continued and a healthy girl was delivered after 41 weeks of gestation.
  
  
  CONCLUSIONS
  This is the first report to indicate a mosaic pregnancy after transfer of a "euploid" blastocyst that was screened by DNA microarray, and the case further confirms that mosaicism is present in human blastocysts produced by in vitro fertilization.
authors.affiliation: Houston Fertility Institute, New Houston Health, 2500 Fondren Rd,, Suite 350, Houston, TX 77063, USA. wangweihua11@yahoo.com.
authors.forename: Ghassan
authors.initials: G
authors.lastname: Haddad
authors.forename: Wenyin
authors.initials: W
authors.lastname: He
authors.forename: Jimmy
authors.initials: J
authors.lastname: Gill
authors.forename: Craig
authors.initials: C
authors.lastname: Witz
authors.forename: Cassie
authors.initials: C
authors.lastname: Wang
authors.forename: Khalied
authors.initials: K
authors.lastname: Kaskar
authors.forename: Weihua
authors.initials: W
authors.lastname: Wang